Manufacture of sheet metal



(No Model) W. GARRETT.

MANUFACTURE OF SHEET METAL; No. 443,137.- Patented Dec. 23, 1890.

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WITNESSES: INVENTOR,

UNITED STATES PATENT OFFICE.

\VILLIAM GARRETT, OF JOLIET, ILLINOIS.

MANUFACTURE OF SHEET METAL.'

SPECIFICATION forming part of Letters Patent No. 443,137, dated December 23, 1890.

Application filed April 23, 1890. Serial No. 349,126. (No model.)

To all whom, it may concern.-

Be it known that I, WILLIAM GARRETT, a citizen of the United States, residing at .loliet, in the county of ill and State of Illinois, have invented or discovered certain new and useful Improvements in the Manufacture of Sheet Metal, of which improvements the following is a specification.

The invention described herein relates to certain improvements in the method of manufacturing metal sheets and tin plates. The method of manufacturing such sheets or plates as at present practiced consists, generally stated, in reducing a bloom or billet about four or five inches square (more orless) to what is termed a sheet-bar, five or six incheswide and one-halfor three-quarters of an inch in thickness, more or less. These bars, when sufficiently cold to handle, are then sheared into blanks of a length dependent upon the width of the sheets or plates desired. The blanks are then placed in a suitable furnace, heated and reduced in suitable rolls to comparatively thin sheets, the blanks being fed sidewise to the rolls. The general practice is to reduce two blanks at a time, the bars following each other in quick succession through the rolls, the upper roll being screwed down after each pass until it is tight against the lower roll. The screws for adjusting the upper roll are then slackened up a little, and the two sheets previously reduced are placed one on top of the other and passed through the rolls, the temperature of the sheets being so reduced in the previous rolling operation as to prevent their welding together. As soon as all the blanks forming one heat or charge of the sheet-bar furnace have been reduced to sheets, as hereinbefore stated, three or four of such sheets are placed one on top of the other, heated in a special furnace, and then rolled as thin as possible. The sheets are then separated, arranged in piles of five or six, again charged into the furnace, heated, and again rolled, and after being thus reduced to the desired gage the edges of the pile or pack are trimmed, thus producing sheets of the required dimensions. It has also been proposed to reduce a slab, bloom, or pile to a plate having a width approximately equal to that of the sheets to be formed, and a thickness and length to produce when rolled sevamount of waste, and, further, when the packs are formed by folding a long sheet, as described, it is impossible to open up the pack-i. a, separate the layers one from the othcras is necessary during the rolling operation, in order to prevent the layers from sticking together.

The present invention has for its object such a method or manner of manipulation as will effect a larger output with less mill-labor, and avoid the great waste heretofore at tending the manufacture of sheet metal, and avoid many of the obstacles heretofore encountered.

In the accompanying drawings, forming, a part of this specification, Figures 1, 3, and L are a plan view of a mill or plant adapted. to the practice of my improved method; and Fig. 2 is a view in elevation of the platingrolls employed in such mill or plant.

In the practice of my invention I take what is commonly known in the art as a nailplate strip, about No. 16 gage in thickness and fifteen inches wide, more or less, and about twenty feet long, and having heated it in a furnace A of suitable length to take the entire strip without bending I pass it lengthwise between a pair of plating-rolls B, the upper roll being screwed down tight, upon the lower roll. The furnace A and all the furnaces hereinafter referred to are open at both ends, in order that the strips may be charged in at one end and withdrawn after heating at the opposite or rear end. The plating-rolls B are arranged in as close proximity to the rear or discharge end of the furnace as is consistent with perfect freedom on the part of the operator in withdrawing the strip or one end thereof out of the furnace and feeding it to the rolls B. By the action of the rolls B the strip is considerably elongated, as well as re duced in thickness, and after it comes from IOC the rolls B it is folded over once, forming a double strip of half the length. The folded strip is then drawn around and charged into the furnace C through its front end. After being properly reheated the double strip is drawn out and passed between the rolls D, which are arranged in the same relation to the furnace C as stated in relation to the rolls 13 and furnace A. The two layers are then opened up, separated at the fold, and then arranged in a pack with two or more strips similarly treated either previously or immediately subsequent to the strip under consideration. The pack thus formed, and consisting of four, six, or more layers, having a width equal to that of the sheets to be formed and of a length sufficient for the production by shearing of anumberof sheets, is then charged into the front end of the furnace E, and after being properly reheated is drawn from the rear end of said furnace and passed between the rolls F. The pack is again opened up, separating the several layers one from the other, and then, the parts being rearranged, charged into the furnace G, reheated, and passed through the rolls H. These operations are continued until the layers forming the pack have been reduced to the desired gage. The pack is then removed to a suitable shearing mechanism, the ends and edges trimmed, and the entire pack divided into sheets by a series of two, three, or more transverse cuts, dependent upon the length of the pack and the lengths of the sheets desired.

It will be readily understood by those skilled in the art that the labor and time consumed in rolling the original strip will be far less than has heretofore been required in rolling down the sheet-bars required to produce the same number of sheets as can be cut from the strip when reduced, and, further, that no more labor or time is required to roll down the packs formed of the long strips than is re quired in rolling the packs in the present practice; and it will be further noticed that in trimming and dividing the strips into sheets there is waste on two edges only of the intermediate sheets and on three edges of the end sheets, Whereas in the present practice there is considerable waste on all four edges of the sheets.

The furnace A is preferably made of a ength sufficient to take in without folding or bending the entire strip with which my method begins; but the other furnaces need be but half or approximately half that length, the strip being folded over, as hereinbefore stated, after passing through the platingrolls B. While preferring to arrange the furnaces and plating-rolls as shown in Fig. l, as such arrangement permits of the driving of the rolls by one engine, and as the charging ends are convenient of access from the point of delivery of each pair of rolls, any other desired arrangement of furnaces and rolls may be employed.

It will be understood that the rolls are so arranged in a manner well known in the art, and shown in Fig. 2, as to draw the sheets or packs from the several furnaces.

The method herein described, while applicable, as described, for the manufacture of tin plates of standard sizei. a, fourteen by twenty inches squareit is more especially applicable to the manufacture of long sheets for roofing purposes. In making such long roofing-sheets the pack, after being rolled to the desired gage, is trimmed along its edges, as described, and is not divided transversely unless the sheets as they come from the last rolls are longer than desired, in which case they may be divided transversely. It will be the usual practice, however, to select a plate of a length and thickness that when divided and reduced in packs in the manner described will produce sheets of the required length.

I claim herein as my invention 1. As an improvement in the art of manufacturing metal sheets, the method herein described, which consists in heating and rolling a metal strip of a width approximately equal to the sheet to be formed and of a gage and length sufficient for the production of four or more sheets of standard size, folding the strip 9 thus reduced once upon itself, heating and rolling the folded strip, dividing the strip along the fold, forming a pack of a series of four or more strips thus produced, heating and rolling the pack until the several layers are reduced to the desired gage, and then trimming the edges of tiepack, substantially as set forth.

2. As an improvement in the art of manufacturing metal sheets, the method herein described, which consists in heating and rolling a metal strip of a width approximately equal to the sheet to be formed and of a gage and length sufficient for the production of four or more sheets of standard size, folding the strip thus reduced once upon itself, heating and rolling the folded strip, dividing the strip along the fold, forming a pack of a series of four or more strips thus produced, heating and rolling the pack until the several layers are reduced to the desired gage, trimming the edges of the pack, and dividing the same into sheets by one or more transverse cuts, substantially as set forth.

In testimony whereof i have hereunto set my hand.

WILLIAM GARRETT.

Witnesses:

S. J. DREW, F. A. JACKSON. 

